Role of endoscopic ultrasound-guided-fine needle aspiration biopsy in the diagnosis of lymphoma of the pancreas: A clinicopathological study of nine cases.

OBJECTIVE: Endoscopic ultrasound-guided-fine needle aspiration (EUS-FNA) is an established first-line procedure in the management of solid and cystic pancreatic masses. Lymphoma is an uncommon diagnosis in EUS-FNA of the pancreas, and it is more common for such a diagnosis to be because of secondary involvement of the pancreas by a lymphoproliferative disorder than for this to represent isolated primary pancreatic lymphoma (PPL). We present the clinical, EUS and cytological features of these lesions.

MATERIAL AND METHODS: After obtaining approval from our Institutional Review Board (IRB), nine cases of lymphoma diagnosed on EUS-FNA at a tertiary care cancer centre over a period of 8 years from 2008 to 2016 were retrieved from our endoscopy and pathology archives. Rapid onsite evaluation (ROSE) was carried out by a trained cytopathologist in all these cases. Cell blocks were available in seven cases, and immunophenotyping was performed on cell blocks using the immunoperoxidase method. Flow cytometry was performed in two cases.

RESULTS: The most frequent site of involvement was the head of the pancreas (n=5, 55.6%). Four out of nine cases were diagnosed as PPL (44.4%). Five cases were diagnosed as lymphoma secondarily involving the pancreas (55.6%). The most frequent diagnosis was diffuse large B-cell lymphoma (n=6, 66.7%), followed by Hodgkin's lymphoma (n=2, 22.2%) and peripheral T-cell lymphoma (n=1, 11.1%).

CONCLUSION: EUS-FNA in experienced hands is a valuable diagnostic modality, in conjunction with ROSE, immunohistochemistry and flow cytometry, in the diagnosis and sub-typing of both primary and secondary pancreatic lymphoma.